In commonly owned U.S. Pat. No. 5,386,883 a lubricant dispenser is described having a vessel adapted to hold a supply of a fluent lubricant and having one side formed with an outlet adapted to be connected via a conduit to a machine to be lubricated and another open side and a cover engaged over the other side and fitted with a cap fittable snugly like a piston in the vessel and forming with the cover a substantially closed compartment holding a supply of a reactive liquid. The cover is formed with a seat opening into the compartment. A gas-generating cartridge fits the seat and has an element or capsule capable of reacting with the liquid and forming a gas. A removable partition closes the seat and segregates it from the liquid-holding compartment. The cartridge is constructed so as to remove the partition and contact the element with the liquid for generating gas in the compartment and forcing the cap like a piston away from the cover into the vessel to pressurize the fluent lubricant therein. The pressurized lubricant flows along a conduit to a machine needing it.
Such a system is very efficient, but occasionally the reactive capsule, typically an active alloy, can hang up in the cell formed by the cartridge and cap. The device must be tapped to get it to drop and start the lubricant-feeding reaction.